Earth Sciences

Building Challenges - Earthquake Resistant Structures

Many cities and towns are built along fault lines, plate boundaries, and tectonically active areas that make them susceptible to tectonic activity. The movement of the plates causes earthquakes, which have had devastating impacts on human settlements. Earthquakes have caused massive loss of human life, billions of dollars worth of damages in property and goods. Today, many scientists and engineers try to create buildings that can withstand the power of the ground underneath our feet shaking and moving and even occasionally cracking and they have come up with many creative solutions.

Depending on the age of your students, ask them to create the parameters for the buildings they will be making or create the parameters yourself. You will want a minimum height and a minimum base square footage. (Low flat buildings are probably pretty earthquake persistent, but they are not very much fun to test and reduce the challenge.) You may want to put a limit on building materials, such as limiting teams to twelve marshmallows and twenty toothpicks, or supplies may be unlimited. The sky is the limit when building your parameters. You can be as complex or as bare bones as you would like.

We had our pre-service elementary teachers build structures with marshmallows, toothpicks, popsicle sticks, binder clips, paper clips, gum drops, and straws. There were many great designs and then we tested them by setting them on a plank on a washtub that was flipped upside down. They were then rocked back and forth violently be one of the supervising professors. If they passed that test, they were forcefully slip forward and back and bounced around. All of our students had produced buildings that could withstand the power of our professor’s earthquakes, even when he accidentally flipped them over.

Nature Demonstration - Tsunamis

Tsunamis are massive waves that tend to be created from some major displacement of water, which can be caused by an earthquake in the ocean, and they cause incredible devastation. There are several recent tsunamis that have captured the attention of the world, such as the tsunami in Japan in 2011. With major cities close to the coasts, it is important that engineers and scientists build and plan developments with these waves in mind.

We introduced tsunami’s using a very long length of coiled wire, much like an oversized slinky. Our students were given the opportunity to hold one end of the wire or the other and then charged with making a wave. They could then try to bunch up the wire and release the pressure and watch the impact grow from the small start. This allowed students to look at how waves behave and what certain influences do to change them.

For the demonstration of a tsunami, our students filled a kiddie pool with sand and built up two beaches that were on opposite sides of the pool from each other. Using rubber corks and other odds and ends from around the lab, they built two communities with large ‘buildings’ both close and far away from the water, as well as bunching up the buildings and spreading them out. The students then began to add water to the pool. To create the tsunamis, they dropped large items into the pool and they also used a wooden board to simulate large waves as a result of tectonic movement and the sea floor shifting. Our students then observed the affects on the two different communities and which communities were impacted more from which wave.

Nature Demonstration - Volcanoes

Volcanoes are a classic science project. Most everyone loves to see things exploding which is why volcano demonstrations are a great way to get students to engage with science. We often forget that there are three different types of volcanoes though. The most popular volcano is the composite volcano and they are built from lava flows, volcanic ash, cinders, blocks, and bombs and create some of our most beautiful mountains. Mount Fuji and Mount St. Helen’s are both composite volcanoes. There are shield volcanoes which are built up from almost entirely fluid lava flows, like we see in the Hawaiian islands. There are also volcanic calderas where most of the magma is under the surface of the earth. A caldera would be Yellowstone National Park.

We tried to create explosions for each of these volcano types. We were unable to truly build a composite volcano eruption, though most of the volcanoes we built resembled them. With baking powder and vinegar, we created lava flows out of a central volcano. Our students also built a series of three volcanoes that exploded with elephant toothpaste (see directions below). Our students had built their volcanoes with an Eirenmeyer flask as the base and the mountain out of playdough. After each eruption, they added new layers of playdough to represent the lava flow. This allowed them to see the growing geology of their volcanoes.

We also built an underwater volcano using candle wax. We placed a tea light that we removed from its metal casing under sand in a beaker. We then filled the beaker and heated it to an extreme temperature. This caused the wax to begin to melt and burst out from the sand to float to the top. While lava would most likely not float to the top of the water, it gave the students an idea of what an underwater volcano might look like and how it might behave.